Pretty sure it wasn't because a lot of originally accepted startups received the rejection email and to be honest it's slightly embarrassing to make such a mist

Pretty sure it wasn't because a lot of originally accepted startups received the rejection email and to be honest it's slightly embarrassing to make such a mistake. However, saying that we're "accepting" all applicants does seem to be an attempt to turn this mistake into something positive, when all that's really changing is that all the applicants get forum access, whereas, only the originally accepted startups still get an advisor (as a part of a group).